Quentin Richardson has a trash-talking history with Paul Pierce and a good resume against LeBron James, especially in his first stint as a Knick.

Richardson, 33, knows he’s here for defense — not his 3-point shot.

He returned for his second stint with the Knicks (2005-09), but hadn’t played since last season with Orlando. He looked light and in shape but his debut was rocky, shooting 1 of 11 (0 of 6 from the 3-point line) in 28:55 of action.

“The one thing I know about this team is they got enough offense,’’ Richardson said before the game. He played extended minutes as Mike Woodson rested his starters.

“I don’t know how much I’ll play, but whatever happens, my first mindset is to be a defensive stopper. We have Carmelo (Anthony), who leads the league in scoring. My first mindset is to play defense.”

Asked about his days defending LeBron when he played for the Knicks, Richardson said, “I do have experience playing against him, that possibly could have factored into it. But if we make it that far, and we get to play them, then I’m up for the challenge.”

* Kenyon Martin won’t put a percentage on his sprained ankle but he said that won’t matter. He will be active on Saturday for Game 1 against the Celtics in the Eastern Conference quarterfinals. He tested it for the first time in running drills yesterday.

“Whatever it is, I’m playing. It don’t matter, you could put a percentage in the paper if you want, but I’m going to play,’’ Martin said. “This is the time of year injuries really don’t matter, especially for me. That’s when I show up and show out. This is what I made my name and money on.”

Martin said the pain after spraining his ankle against the Wizards eight days ago was akin to when he tore his ACL while he was a senior at Cincinnati in 2000.

“I wasn’t in that much pain when I did that,’’ Martin said. “The worst thing went through my mind. X-rays were negative. It was a huge relief. When I was hitting the floor, it wasn’t just an act. I was in dire pain.’’

* Coach Mike Woodson on playing in Boston next week amid the Boston Marathon bombing:

“It’s a sad time in Boston. My prayers go out to the victims. Boston has always been a sports town. They’ll rally around and try to figure it out. It’s going to be a tough, hostile environment anyway. They have great fans.’’